Opaque Key Prefix Rebase

Description

Rebase literal opaque key prefixes only when every supplied key matches the explicit old prefix; no path normalization, substring replacement or inferred aliases.

An opaque key’s representation can affect equality and ordering even when its underlying value is unchanged. Delimiter joining can be ambiguous, fixed-width padding can preserve numeric order within agreed bounds, and typed length-prefix framing keeps scalar types distinct. Lengths in this family count UTF-16 code units unless a different unit is stated.

Rebase literal opaque key prefixes only when every supplied key matches the explicit old prefix; no path normalization, substring replacement or inferred aliases.

When to use this tool

Use this tool to rebase literal opaque key prefixes only when every supplied key matches the explicit old prefix; no path normalization, substring replacement or inferred aliases.

How to use the tool and how it works

Enter keys, oldPrefix, newPrefix using the field definitions below.
Run the operation. Correct input errors before interpreting an output.
Read result.keys. Use the ordering, boundary rules and absence conditions described below.

Require a nonempty oldPrefix and require every key to begin with it, then replace that occurrence with newPrefix.^[1]

Input field	Meaning and units	Accepted input
keys	Opaque key strings in original order.	Dense list of at most 128 strings, each at most 8,192 UTF-16 code units.
oldPrefix	Required nonempty source prefix.	Text, at most 8,192 UTF-16 code units; the operation’s grammar also applies.
newPrefix	Replacement prefix; may be empty.	Text, at most 8,192 UTF-16 code units; the operation’s grammar also applies.

Output field	Interpretation
result	Object containing the named fields below.
result.keys	Transformed opaque key strings in original order.

json

{
  "input": {
    "keys": [
      "old/a",
      "old/b"
    ],
    "oldPrefix": "old/",
    "newPrefix": "new/"
  },
  "output": {
    "result": {
      "keys": [
        "new/a",
        "new/b"
      ]
    }
  }
}

Limitations and assumptions

A mismatching key causes an error; this does not perform arbitrary substring replacement.
String framing and alphabet digits use UTF-16 code units, not bytes or grapheme clusters. Exact integer text accepts a signed decimal spelling of at most 256 digits before operation-specific range checks.
Every declared top-level input field is required and unexpected fields are rejected. Ordinary strings are limited to 8,192 UTF-16 code units and lists to 128 entries, with tighter operation-specific bounds where stated. JSON text has bounded nesting and node counts.
Numeric outputs must be finite and no larger in absolute magnitude than the safe-integer limit; operations returning exact large integers use decimal text. Positions are zero-based and spans end exclusively unless the operation explicitly states a different convention.

Alternative or Complementary methods

Use typed framing when distinct scalar types or tuple boundaries must remain distinguishable. Keep alphabet, width, normalization and numeric bounds consistent between producers and consumers.

References

Tool behavior and example: Opaque Key Prefix Rebase — tool.io

Similar or alternative tools

Opaque Key Affix Normalizer
Ensure caller prefix and suffix are present after stripping/reapplying at most one matching affix; repeated inner affixes remain literal data, no recursive stripping or path semantics.
Opaque Key Alphabet Audit
Audit opaque key UTF-16 code units against an explicit caller alphabet with positions; not Unicode grapheme, entropy or checksum validation.